Distributing switch



Patented Feb. 5, '1924.

UNITED STATES` 1,482,625 PATENT OFFICE.

GEORGE THOMPSON, OF MOUNT VERNON, NEW YORK, ASSIGNOR TO WESTERN ELEC- TRIO COMPANY, INCORPORATED, OF YORK, N. Y., A CORPORATION OF NEW YORK.

DISTRIBUTING SWITCH.

Application nled September 4, 1919. Serial No, 321,651.

T 0 @ZZ whom it may concern:

Be it known that I, GEORGE T HoMrsoN,` a citizen of the United States, residing 'at Mount Vernon, in the county of Westchester, State of New York, have invented certain new and useful Improvements in Distributing Switches, of which the following is a full, clear, concise, and exact description.

This invention relates to automatic telephone exchange systems and more particularly to the mechanical construction of, and the arrangement of electrical circuits for, a switch suitable for use in such systems.

An object of this invention is to provide a switch which shall be simple in construction and rapid in operation.

The switch of the present invention is an improvement on that shown in Patent No. 1,375,762, issued April 26, 1921, and possesses all of the advantages of such switch with the additional advantage that the magnets which were used to mechanically withdraw the circuit closers from the path of the operating elements are eliminated in the present invention.

The switch is provided with three movable cont-act operating members in fixed relation to one another. The switch is designed primarily for use as a hunting switch, and the peculiar angular relation between these three contact operating members and the sets of contacts arranged for cooperation with them is such that whichever contact operatin member first reaches a line in the desired electrical condition, will o erate the contacts of such line. AS a resu t of this arrangement, fewer steps are necessary before a line in the desired condition can be seized.

A switch of this type has aV further advantage which'is also due to the peculiar angular relation between the contact sets and the contact operating members. As a result of this arrangement, the outgoing lines will not be tested in a predetermined order and, therefore, the apparatus associated with such outgoing lines will receive approximately e ual shares of the work which is to be distributed to them by the switch.

A features of the invention resides in the fact that a plurality of normal positions are provided for the switch and that the switch will be advanced out of these normal positions between testing operations in accordance with the electrical condition of the incoming line.

The switch, as shown and described, is intended for use primarily as a distributing switch individual to a calling subscribers line. It is obvious, however', that a switch of this character is adapted to a variety of uses and the invention is, therefore, to be restricted only by the appended claims.

Itis thought that the invention will be best understood from the following detailed description, reference being had to the accompanying drawings.

ln the drawings, tig. 1 shows operating circuits for a switch embodying the features of the present invention, and Fig. 2 shows such portions of the switch mechanism as are necessary to an understanding of the operation of the switch.

The mechanical construction of the switch willl first be described. Referring now to Fig. 2a shaft l is rotatably mounted on bearings of any suitable character. Secured to such shaft and rotatable therewith is a yoke provided with arms 8, 4 and 5. The arms 3, f1 and 5 project radially from the center of rotation andare spaced apart equal angular distances. Since the three arms are spaced equally in the circumferenceI of a circle, it is obvious that the angular distance between the arms is 120.

`Fixedly secured to the shaft 1 is a ratchet wheel 6 which may be rotated in a clockwise direction under the control of a stepping pawl 7 mounted on the armature 8 of `arranged to be operated by cams 12, which cams are carried on each of the arms 3, 4 and 5, respectively.

Since the Contact sets are placed equally about the circumference of the `circle and are ten in number, it follows that the angular distances between adjacent contact sets is 36D. The ratchet wheel 6 is designed to have sixty teeth so that the contact-operatin-fr members will be advanced GO at each s of the rachet Wheel.

It Will be assumed that the various points, about the circumference of the circle described by the arms 3, et and 5 during;` rotation, at which contact sets 10 are located, are, indicated by the letters A, B, C, D, E, l?, (if, H, M and N respectively. l't Will further be assumed that at the time a call is initiated, the position o1 the f'arious arms with respect to these contactsets is as shovrn in the dra\vings. By recalling that thecontact sets are 36C apart, it will be obvious that it arm 3 must be advanced one step to operate the contacts` at A, then the contact arm el will be one'step in advance oi position D and arm will be three steps iu advance ot position G.

When the subscriber initiates a call, trie arms- 3, l and 5A will be advanced, due to the closure of a circuit completed through the contact set l0 vvnich is in operated condition, due to the action of cam 12 on arm 3. The switch is advanced one step whereupon the conta-cts l0 at position A. are operated to complete a testing circuit. It the trunk associated with the contact set. at it. is busy, the Switch isfoaused to maire another step Whereupon cam 12 on ar1n5 will operate contact set e0 at'position H. Due fto the caliing,` condition of. the line, the switch will be advanced another step to operate Contact sets at H and another test made. Upon completion of the conversation, the switch is advanced onestop. Inspection ot the dreiving will show that Whenever the switch is released, regardless of which arin and which contact set is utilised, there will always be an arm Within one step of a` contact set 10, which means that an associated contact set 40`Will be in an operated condition to cause the advance of' the switch when the calling subscriber removes his receiver from the switchhool.

Reverse movement and overthrow are prevented by the action of holding pawl 13 which cofoperates Wit-h the ratchet Wheel 6.

The operating circuits ot the switch Will now be described, reference being had to Fig. 1. When the subscriber Whose substation is indicated at 14 removes his receiver troni the switchhoolr, circuit is completed frein grounded'battery, right-hand Winding of differential.stepping magnet 9, outer left hand armature and blick Contact ot cutod relay 15, springs 16 and 17 oi". an operated set `l0,conductor1S, through` the calling substation, conductor 19, springs 20 and 21 of the operated set 40, outermost righthand armature.V and back Contact of cut cutoi'l relay 15 toground. Stepping magnet is energized in this circuit and advances the switch one step,.thus openingfcontact l0 and closing Contact. set-l0.. lit-he;truulmvith which this -Will be ground on contact 26.

particular set l0 is nessociated is idle, there Circuits are then completed through both windings of differential magnet 9, thus preventing the energization ot this magnet and causing the switch to remain in this position. The circuit through the righihand Winding oi magnet E) at this time extends trom grounded battery, right-hand Winding ot magnet 9, actuated springs 23 and 2e, outermost righthand armature and haci: contact of cutoii relay l5 to ground. The circuit 'through the left-hand Wind' q or magnet 9 extendsl from grounded battery, leftehand Windingl of magnot 9, right-handWinding of cutoff relay 15, springs 25, 26, to ground at the armature and'baclr contact relay 2S. As previously stated, magnet 9 is not energizedin this cir` cuit, but cutoff relaT 15 is energized and completes a loclri g circuit for itself extending from groten Vvd battery, Winding ot relay 28, springs 3l, 32, inner lett-hand armature, front Contact and'lct-hand .vinding' of relay to ground. lelay 28 is eneregized in this circuit and removes the ground from the inuiiple test terminal 26 of the trunlrto render the trunk busy to other hunting` switches. Relay l5 at its inner and'middle right-hand armatures extends the calling subscribei"s line to the trunk by Way oi contacts 17 and 32. and 34tand 35, and 3,6 and 3T.

ln case the trunk4 had been busy, the above traced circuit through the left-hand winding of magnet 9 would have been open at the contact of relay 28. The circuit through the right-hand Winding ofmagnet 9 would, therefore, have caused the switch to be advanced another step, at which time another set of contacts 40 would havel been closed to advance the switch dueto the closure of a circuit similar` to the circuit` previously described when the subscriber removed his receiver from the switchhook. In this Way, the switch is caused toY advance until an idle trunlris found.

lWhen conversation is completed and the calling subscriber replaces his receiver, the circuit ofV relay 28 is broken at the Erstselector switch in any desired rWell-lrnovv'n manner. At the same time the circuit of cutoff relay 15 isl broken and this relay deenergizes. Relav28 is a slow-to-release relay and before itsarmature is retracted, a. circuit is completed from grounded battery, righthand windingot stepping magnet 9, closed contacts 23 and 2e, outer-right-hand armature and back contact of relay 15 to ground. This circuit is-eieetive to energize the stepping magnet and cause the switch to advance one step, Where it will remain until the calling subscriber again removes hisv receiver from the switchhook. When relayv 28 fully retracts its armature, no circuit isconipleted for steppingymagnet v9, at Athis time the contact-.operating llO member l1 will have been advanced and springs 25 and 26 will be out of engagement with each other.

In case the line is seized as a called line by a connector switch, battery supplied through the connector switch to test terminal 38 causes the energization of cutoff relay 15, thus removing the control of the stepping magnet 9 from the calling subscriber when he removes his receiver from the switchhook to answer the call.

What is claimed is:

1. In an automatic switch, a plurality of fixed resilient contacts, a plurality of operf ating members in fixed relation to one ann tive relation with ot ers of said contacts before said first member is brought into operative relation with another of said conv tacts.

2. In an automatic switch, a plurality of sets of xed resilient contacts arranged in the arc of a circle, a plurality ofy rotatable members in fixed angular relation to one another and in operative relation to said fixed contacts, means to complete electrical circuits through said fixed contacts when operated by said members by virtue of the resiliency of said contacts, step-b step mechanism to control the advance o said members, means to advance a given one of said members from one of said contact sets to the next as a result of a plurality of steps by said step-by-step mechanism, means to bring said members successively into operative relation with any one of said fixed contact sets, and means t0 bring each of the other operatin members into operative relation with ot ers of said contacts before said first member is brought into operative relation with another of said contacts.

3. In an automatic switch, a plurality of main circuit closers, a plurality of auxiliary circuit closers, means to alternately operate said main circuit closers and said auxiliary closers, said means including a plurality of operating members in fixed relation to one another, certain ones of said operating members being arranged to operate said main circuit closers and others of said operating members being arranged to operate said auxiliar circuit closers.

In Wit-ness whereo I hereunto subscribe my name this 28th day of August, A. D.

GEORGE THOMPSON. 

